DELTA-SIGMA MODULATOR AND DITHERING METHOD HAVING DITHERING CAPABILITY FOR ELIMINATING IDLE TONES Russian patent published in 2012 - IPC H03M3/02 

FIELD: information technology.

SUBSTANCE: delta-sigma modulator includes a bitstream converter configured to generate a digital signal output substantially corresponding to an analogue signal input, a periodicity detector connected to the bitstream converter and configured to detect periodicity in the digital signal output, and a dithering sequence generator connected to and activated by the periodicity detector. The dithering sequence generator generates a dithering sequence. The delta-sigma modulator further includes a pulse-width modulation (PWM) generator connected to the dithering sequence generator and receiving the dithering sequence. The PWM generator modulates the dithering sequence onto the analogue signal input of the delta-sigma modulator as a dithering signal.

EFFECT: generation of a dithering signal at the required time which improves signal quality.

12 cl, 4 dwg